It has been known in the prior art to provide for utilization of roller clutch devices in a torque transfer mechanism to drive tandem parallel driving axles. The use of the one-way structure simplifies the mechanism used to split the driving torque between the axles in that the more complex standard differential mechanism, such as a bevel gear differential, is replaced by the one-way device. However, the use of the one-way device in this configuration in which normally a pair of roller clutches are utilized induces a problem in that improper relationships can develop due to one of the one-way devices locking up in the wrong direction of relative rotation. This has lead to a structure wherein forward and reverse roller clutches are used and a shift lever must be provided to selectively activate one or the other of the one-way devices. The present invention provides a unique solution to this problem by eliminating the necessity for a shifting mechanism.